Odontoid Fractures: A Standard Review of Current Concepts and Treatment Recommendations

Comparison of iCT-based navigation and fluoroscopic-guidance for atlantoaxial screw placement in 78 patients with traumatic cervical spine injuries

BACKGROUND CONTEXT

Studies have shown biomechanical superiority of cervical pedicle screw placement over other techniques. However, accurate placement is challenging due to the inherent risk of neurovascular complications. Navigation technology based on intraoperative 3D imaging allows highly accurate screw placement, yet studies specifically investigating screw placement in patients with traumatic atlantoaxial injuries are scarce. The aim of this study was to compare atlantoaxial screw placement as treatment of traumatic instabilities using iCT-based navigation or fluoroscopic-guidance with intraoperative 3D control scans.

METHODS

This was a retrospective review of patients with traumatic atlantoaxial injuries treated operatively with dorsal stabilization of C1 and C2. Patients were either assigned to the intraoperative navigation or fluoroscopic-guidance group. Screw accuracy, procedure time, and revisions were compared.

RESULTS

Seventy-eight patients were included in this study with 51 patients in the navigation group and 27 patients in the fluoroscopic-guidance group. In total, 312 screws were placed in C1 and C2. Screw accuracy was high in both groups; however, pedicle perforations > 1 mm occurred significantly more often in the fluoroscopic-guidance group (P = 0.02). Procedure time was on average 23 min shorter in the navigation group (P = 0.02).

CONCLUSIONS

This study contributes to the available data showing that navigated atlantoaxial screw placement proves to be feasible as well as highly accurate compared to the fluoroscopic-guidance technique without prolonging the time needed for surgery. When comparing these data with other studies, the application of different classification systems for assessment of screw accuracy should be considered.

Posterior-only approach for treatment of irreducible traumatic Atlanto-axial dislocation, secondary to type-II odontoid fracture; report of a missed case, its management and review of literature

INTRODUCTION AND IMPORTANCE

Odontoid fracture (OF) is among the most common and challenging cervical spine fractures in regards to the treatment and surgical approach. Atlanto-axial dislocation (AAD) is considered a significant complication after failed non-surgical treatment of OF. Traditionally, it requires anterior odontoidectomy followed by posterior C1-C2 reduction and fusion. In latest studies, Atlanto-axial joint (AAJ) remodeling in a posterior-only approach has got attention.

CASE PRESENTATION

We herein present a 30-year-old man with missed type-II OF, presenting with irreducible anterior AAD and progressive neurological deficit. Old non-united OF with dorsal callous formation, compressing spinal cord, was detected. The patient underwent correction of the deformity and reduction of the fracture utilizing the posterior-only approach. AAJ remodeling, callous release and C1-C2 fusion was performed in standard prone position, under fluoroscopic guide and intraoperative electrophysiological monitoring. The patient had uneventful surgery and postoperative course and was neurologically intact with appropriate alignment in 6-month follow-up.

CLINICAL DISCUSSION

The irreducible AAD following type-II OF could be successfully treated with posterior-only approach (C1-C2 fusion).

CONCLUSION

Type-II OF is considered unstable requiring surgical management. Close follow-up and appropriate patient education is mandatory in non-surgical treatment. Irreducible AAD has been managed with anterior odontoid resection and posterior fusion. Several complications of anterior surgery, makes posterior-only approach a noticeable choice.

Odontoid/Dens Fractures

Odontoid fractures remain the most common C2 fracture and of those individuals older than 65 years. The type of optimal management remains in question given comorbidities, risk of nonunion, and limitations in mobility when surgical fusion is the treatment selected. These fractures are of particular importance, given the high incident of morbidity and mortality following an odontoid fracture. Overall quality of life remains a significant consideration when selecting the best intervention following careful examination and confirmation with radiographic imaging. The literature continues with controversies in the best treatment interventions for these fractures, resulting in a case-by-case decision-making process.

Epidemiology of C2 fractures and determinants of surgical management: analysis of a national registry

Objective

Operative management of axis fractures (C2) usually depend on the stability and location of the break and individual patient characteristics. We sought to describe the epidemiology of C2 fractures and hypothesized that determinants for surgery would differ by fracture diagnosis.

Methods

Patients with C2 fractures were identified from the US National Trauma Data Bank from January 1, 2017, to January 1, 2020. Patients were classified by C2 fracture diagnosis: odontoid type II, odontoid types I and III, and non-odontoid fracture (hangman's fracture or fractures through base of the axis). The primary comparison was C2 fracture surgery versus non-operative management. Multivariate logistic regression was used to identify independent associations with surgery. Decision tree-based models were developed to identify determinants for surgery.

Results

There were 38 080 patients; 42.7% had an odontoid type II fracture; 16.5% had an odontoid type I/III fracture; and 40.8% had a non-odontoid fracture. All examined patient demographics, clinical characteristics, outcomes, and interventions differed by C2 fracture diagnosis. Overall, 5292 (13.9%) were surgically managed (17.5% odontoid type II, 11.0% odontoid type I/III, and 11.2% non-odontoid; p<0.001). The following covariates increased odds of surgery for all three fracture diagnoses: younger age, treatment at a level I trauma center, fracture displacement, cervical ligament sprain, and cervical subluxation. Determinants of surgery differed by fracture diagnosis: for odontoid type II, age ≤80 years, a displaced fracture, and cervical ligament sprain were determinants; for odontoid type I/III, age ≤85 years, a displaced fracture, and cervical subluxation were determinants; for non-odontoid fractures, cervical subluxation and cervical ligament sprain were the strongest determinants for surgery, by hierarchy.

Conclusions

This is the largest published study of C2 fractures and current surgical management in the USA. Odontoid fractures, regardless of type, had age and fracture displacement as the strongest determinants for surgical management, whereas associated injuries were determinants of surgery for non-odontoid fractures.

Level of evidence

III.